Inhibited distillate fuels



Patented Dec. 29, 1964 3,163,505 HJHIEITED DESTHLLATE FUELS Harry J. Andreas, in, Pittman, and Paul Y. Q. Gee, Woodhury, N..i., assignors to Soceny Mobil Gil Company, line, a corporation of New York No Drawing. Filed Aug. 7, 1961, Ser. No. 129,514 Claims. (Cl. 44-70) The present invention relates to improved nonlubricating petroleum fractions and, more particularly, to nonlubricating petroleum distillates such as fuel oils containing certain additives as inhibitors against screen clogging, gasolines inhibited against formation of deposits in carburetors of gasoline engines and imparted with anti-stall characteristics.

It is Well known that fuel oils (i.e.; heater fuels, jet fuels, etc.) are prone to form sludge or sediment during periods of prolonged storage whereby burner operations are adversely affected due to clogging of screens and nozzles. Additionally, such fuel oils may contain other impurities such as rust, dirt and entrained water. The sediment and impurities tend to settle out on equipment parts (nozzles, screens, filters, etc.) to the extent of causing the equipment to fail due to clogging. Another factor, incident to the storage and handling of distillate fuels (i.e., gasoline, fuel oils) is the breathing of storage vessels which results in accumulation of considerable amounts of water in the tanks thereby presenting a problem of rusting of the tanks. Thus, when the fuel is removed for transportation, sufficient water may be carried along to cause rusting of ferrous metal surfaces in pipelines, tankers, and the like.

Generally speaking, in the case of fuel oils, it has been the practice to overcome the aforedescribed difficulties with a separate additive for each purpose. The use of a plurality of additives, however, gives rise to problems of additive compatability whereby the choice of additive combinations becomes restricted and, obviously, the cost of the fuel unduly increases. It is highly desirable,.therefore, to employ a single additive that is effective to inhibit the fuel oil against a plurality of the aforedescribed difiieulties and, particularly, against screen and nozzle clogging and rusting of ferrous metal surfaces.

As to the motor fuels, e.g., gasolines, it is highly desirable that the gasolines, over and above being inhibited against rusting of ferrous metal surfaces, should provide improved operation of internal combustion engines by possessing anti-stall characteristics as well as being inhibited against formation of deposits in carburetors.

In reference to gasolines, it is known to those skilled in the art that frequent stalling of automobile engines, especially during the warmup period, has been a common occurrence. This difiiculty is most pronounced in postwar cars having automatic transmissions and a consequent limit on the maximum permissible idle speed, although it also occurs in cars without automatic transmissions. Stalling of this type, of course, is a definite safety hazard, as well as a decided inconvenience in frequent restarting of the engine.

It is now recognized that stalling during the warmup period is attributable to the formation of ice on the throttle plate and the carburetor barrel near it. The water which forms the ice does not generally come from the gasoline, i.e., as entrained water, but from the air that enters the carburetor. Stalling generally occurs in cool, humid weather, when the temperatures are above 30 F. and below about 60 F. and the relative humidity is about 65 percent and higher, up to 100 percent. The most critical conditions are temperatures of 35-40 F. and 100 percent relative humidity.

As the gasoline evaporates in the carburetor, it reduces the temperature of the surrounding metal by as much as 40 F. Moisture in the incoming air comes in contact with these parts and begins to build up ice on the throttle plate and in the carburetor barrel. The more moist this air is, the greater the buildup of ice. Then, when the engine is idled, the throttle plate closes and the ice chokes off the normal small flow of air through the small clearance between the throttle plate and the carburetor wall. This causes the engine to stall. e engine can usually be restarted when the heat from the exhaust manifold melts the ice sufficiently. However, stalling will continue until the engine is completely warmed up.

Icing may also occur in the carburetors of some vehicles when cruising at speeds of 30-60 mph. Such icing is a particular problem in the case of certain trucks and cars equipped with carburetors having Venturi-type fuel-air mixing tubes (emulsion tubes). Such carburetors are found in trucks and in many European cars. The ice builds up in the tube and restricts the flow of air, thereby enriching the fuel mixture and reducing eificiency. Eventually the engine may stall. With further reference to gasoline it is also known to those skilled in the art that during operation of sparkignited internal combustion engines, deposits build up in the throttle body area of the carburetor. These deposits are attributable to foreign matter introduced into the carburetor through the air intake and not to the components of the gasoline itself. The major contributors are blowby and crankcase fumes which emit from the crankcase vent, collect under the hood, and are pulled into the air intake. Another factor contributing to deposits is air pollution. This can be because of general-contaminants in the atmosphere, such as industrial Wastes, or it can be because of exhaust gases, particularly in stop and go driving in heavy traffic.

As they accumulate, these deposits cause rough idling and necessitate frequent adjustment of the idle air bleed screw. Eventually the engine will fail to idle and the carburetor must be removed and cleaned. In extreme cases, it may even be necessary to replace the carburetor. The formation of heavy carburetor deposits is most pronounced in vehicles that are operated at idle speeds for a large portion of the time, such as taxicabs, local doorto-door delivery trucks, and passenger cars used in congested areas in stop-and-go traffic. Although the problem of carburetor deposits is rather widespread, the nature of the deposits vary in different localities. Thus, smog appears to accelerate the formation of deposits, that are tacky and less carbonaceous. On the other hand, in relatively smog-free areas, the deposits Will be dry, hard, and carbonaceous. Whatever the type of deposit, however, the build-up of deposits in the carburetor adversely affects engine performance. Particularly in the case of commercial fleet operation, carburetor deposits greatly increase maintenance costs. Accordingly, it is highly desirable to provide a means of inhibiting the formation of carburetor deposits.

It has now been found that non-lubricating petroleum fractions can be inhibited, by use of a single additive, against the afore stated difliculties. In accordance With this invention, the desired improve meats in non-lubricating petroleum distillates are obtained by incorporating in such distillates a small amount of a substituted butyric acid derivative of the following structure:

R x oorncrnomoo0H)n in which R is alkyl and x and n are the same or different whole numbers of not more than 2. In such compounds, R may for example, be an alkyl group of from 4 to 18 carbon atoms and, more specifically, from 8 to 12 carbon atoms as in octyl, nonyl, dodecyl groups with x and n being 1 or 2 or combinations thereof. More specific examples embodied for use in practice of this invention include alkylphenoxybutyric acids such as octylphenoxybutyric acid, nonylphenoxybutyric acid, dinonylphenoxybutyric acid, and dodecylphenoxybutyric acid; alkyl resorcinoxybutyric acid and alkyl-catechoxybutyric acid such as nonyl resorcinoxybutyric acid, nonyl catechoxybutyric acid, dodecyl resorcinoxybutyric acid, dodedecyl catechoxybutyric acid and others.

Although the aforesaid compounds useful for practice of this invention can be prepared by any of several methods known to those skilled in the art, a suitable method is the reaction of an alkyl phenol with sodium hydroxide to form a sodium alkylphenoxide followed by heating the latter with butyrolactone, and then acidifying (e.g., HCl) the resulting product, to produce the free organic acid. Thus in more specific illustrations, an alkylphenoxybutyric acid can be prepared by reacting a sodium alkylphenoxide, at 125-200 (3., for 25 hours, with an equimolar amount of butyrolactone, and acidifying the resulting sodium salt to produce the alkylphenoxybutyric acid; and in the same manner, the alkyl resorcinoxybutyric acid and the alkylcatechoxybutyric acids can be prepared by reacing one mole of their sodium salts with two moles of butyrolactone and then acidifying with hydrochloric acid.

The distillate fuels that are improved in accordance with the present invention are the distillate fuel oil and aviation and motor gasoline. The distillate fuel oils are hydrocarbon fractions having an initial boiling point of at least about 100 F. and an end boiling point no higher than about 750 F., and boiling substantially continuously throughout their distillation range. Such fuel oils are generally known as distillate fuel oils. It is to be understood, however, that this term is not restricted to straight-run distillate fractions. The distillate fuel oils can be straight run distillate fuel oils, catalytically or thermally cracked (including hydrocracked) distillate fuel oils, or mixtures of straight-run distillate fuel oils, naphthas and the like, with cracked distillate stocks. Moreover, such fuel oils can be treated in accordance with well known commercial methods, such as, acid or caustic treatment, hydrogenation, solvent refining, clay treatment, etc.

This distillate fuel oils are characterized by their relatively low viscosities, pour points, and the like. The principal property which characterizes the contemplated hydrocarbons, however, is the distillation range. As mentioned hereinbefore, this range will lie between about 100 F. and about 750 F. Obviously, the distillation range of each individual fuel oil will cover a narrower boiling range falling, nevertheless, within the abovespecified limits. Likewise, each fuel oil will boil substantially continuously throughout its distillation range.

Particularly contemplated among the fuel oils are Nos. 1, 2 and 3 fuel oils used in heating and as Diesel fuel oils, and the jet combustion fuels. The domestic fuel oils generally conform to the specifications set forth in ASTM Specifications D396-48T. Specifications for Diesel fuels are defined in ASTM Specifications D975- 48T. Typical jet fuels are defined in Military Specification MILF-5624B.

The gasolines are mixtures of hydrocarbons suitable for use in internal combustion engines of the spark-ignition type. These fuels include both motor gasolines and aviation gasolines. In general, motor gasolines have an initial boiling point as low as about 75 F. and an end-boiling point as high as about 450 F. and boil substantially continuously between the initial boiling point and the endboiling point. Aviation gasolines, on the other hand, are mixtures of hydrocarbons having an initial boiling point of about 80 F. and an end-boiling point of about 340 F., and boil substantially continuously between these points.

The amount of the aforedefined additives that is incorporated into the petroleum distillates in accordance with this invention will depend upon the intended purpose and the particular composition of the additive as they are not all equivalent in their activity. Thus, some may have to be used in lesser or greater concentrations than others. In many cases, in which it is desired to obtain a plurality of beneficial results in fuel oils, namely to reduce screen clogging and inhibit against rusting of ferrous metal surfaces, additive concentrations varying between about 10 pounds/ thousand barrels of fuel oil and about 200 pounds/ thousand barrels of fuel are employed. In cases wherein it is desired not to accomplish both of such results, and particularly in gasolines, lower concentrations can often be used with satisfactory results. Thus, as an example, if it is desired only to inhibit against rusting, under dynamic conditions, as in a pipeline, concentrations as low as about 2.5 parts/million, i.e.-ab0ut 0.5 pound of additive/ thousand barrels of the petroleum distillate are generally effective. Hence, in general, the amount of the additive embodied herein that is added to the petroleum distillate, in order to achieve a beneficial result, will vary generally between about 0.5 pound to about 200 pounds/thousand barrels of the distillate and, preferably, between about 10 and about 200 pounds/thousand barrels of the distillate.

If it is desired, the distillate fuel compositions can contain other additives for the purpose of achieving other results. Thus, for example, there can be present foam inhibitors, ignition and burning quality improvers, scavengers, and preignition agents. Examples of such additives are silicones, dinitropropane, amyl nitrate, metal sulfonates, lead tetraethyl, haloalkanes, phosphate esters, and the like. 7

The following specific examples are for the purpose of illustrating the petroleum distillate compositions of this invention. It should be understood, therefore, that this invention is not to be limited to the particular additives and distillates defined therein as other additives and distillates, as discussed hereinbefore can be used as will be appreciated by those skilled in the art.

In the following, Example Nos. 1 to 4, set forth preparations of specific additives embodied for use in practice of this invention.

EXAMPLE 1 Dinonyl Phenoxybutyric Acid A mixture of 346 gms. (1 mole) of dinonyl phenol and 40 gms. (1 mole) of sodium hydroxide dissolved in isopropanol was gradually heated to C. to form the sodium dinonyl phenoxide. The sodium dinonyl phenoxide was then cooled to 50 C. at which a quantity of 86 gms. (1 mole) of butyrolactone was added with stirring. The mixture was gradually heated to 175 C. and was held at 175 C. for 3 hours to insure the complete formation of the sodium dinonyl phenoxybutyrate. The sodium dinonyl phenoxybutyrate was then cooled to about 100 C. and acidified with hydrochloric acid. The product, dinonyl phenoxybutyric acid, being viscous, was diluted with toluene, filtered through Hyfio clay and distilled to C. under vacuum of about 40 mm. Hg.

EXAMPLE 2 Dodecyl Phenoxyb utyric Acid A mixture of 300 gms. (1 mole based on OH No. of dodecyl phenol and 40 gms. (1 mole) of sodium hydroxide dissolved in n-butanol was gradually heated to 200 C. to form the sodium dodecyl phenoxide. The sodium dodecyl phenoxide was then cooled to 75 C. at which a quantity of 86 gms. (1 mole) of butyrolactone and 150 cc. of xylene were added with stirring. The mixture was refluxed at 140 C. for 5 hours to form the sodium dodecyl phenoxybutyrate. The sodium dodecyl phenoxybutyrate was cooled to 80 C. and acidified with 5 hydrochloric acid. The product, dodecyl phenoxybutyric acid, was filtered through Hyflo clay and distilled to 175 C. under vacuum of about 40 mm. Hg.

EXAMPLE 3 Nonyl Resoreinoxybutyric Acid A mixture of 248 gms. (0.53 mole based on OH N0. 239) of nonyl alkylated resorcinol and 42.5 gms. (1.06 moles) of sodium hydroxide dissolved in n-butanol' was gradually heated to 200 C. to form the salt of nonyl resorcinol. The sodium salt of nonyl resorcinol was cooled to 100 C. at which a quantity of 91.5 gins. (1.06 moles) of butyrolactone, diluted with about 150 cc. of Xylene, was added with stirring. The mixture was stirred at 140 C. for 6 hours to form the sodium nonyl resorcinoxybutyrate. The sodium nonyl resorcinoxybutyrate was cooled to 90 C. and acidified with hydrochloric acid. The product, nonyl resorcinoxybutyric acid, was filtered through Hyilo clay and distilled to 175 C. under vacuum of about 40 mm. Hg.

EXAMPLE 4 Nonyl Catechoxybutyric Acid A mixture of 300 gms. (0.76 mole based on OH No. 284) of nonyl alkylated catechol and 61 gms. (1.52 moles) of sodium hydroxide dissolved in n-butanol was gradually heated to 155 C. to form the sodium salt of nonyl catechol. To the sodium salt of nonyl catechol was added 130 gms. (1.52 moles) of butyrolactone at 80 C. with stirring. The mixture was stirred at 135 C. for 5 hours to form the sodium nonyl catechoxybutyrate. The sodium nonyl catechoxybutyrate was cooled and acidified with hydrochloric acid. The product, nonyl catechoxybutyric acid, was filtered through Hyfio'clay and distilled to 180 C. under vacuum of about 40 mm. Hg.

In the following, Example No. 5 illustrates the improvement that is obtained by practice of this invention with respect to inhibiting fuel oils against screen clogging and rusting characteristics. The'tests employed to determine such characteristics are described in the following.

Screen Clogging of Fuel Oils The test is conducted using a Sundstrand V or S1 home fuel oil burner pump with a self-contained l-mesh Monel metal screen. About 0.05% by weight, of natural ly-formed fuel oil sediment, composed of fuel oil, water, dirt, rust, and organic sludge is mixed with 10 liters of the fuel oil and the mixture is circulated by the pump through the screen for 6 hours. The sludge deposited on the screen is washed oif with n-pentane and filtered through a tared Gooch crucible. After drying, the material in the Gooch crucible is washed with a 50-50 (volume) acetone-methanol mixture. The total organic sediment is obtained by evaporating the pentane and the acetone-methanol filtrates. Drying and weighing the Gooch crucible yields the amount of inorganic sediment. The sum of the organic and inorganic deposits on the screen can be reported in milligrams recovered or converted into percent screen clogging.

EXAMPLE Screen Clogging Tests in. mercury manifold pressure.

6 Rust Test in Fuel Oil The rusting characteristics of fuel oils were determined in the Static Rust Test, which simulates conditions encountered in storage vessels, such as the home fuel storage tank. In this test, a strip of 16-20 gauge sand blasted steel plate is placed in a clear quart bottle. The length of the strip is sufficient to reach from the bottom into the neck of the bottle without interfering wih the cap. One hundred cc. of synthetic sea water with pH adjusted to 5 (ASTM 13-665) and 750 cc. of test oil are placed in the bottle. The bottle is capped tightly, shaken vigorously for one minute, and permitted to sand quietly at 80 F. for 21 days. At the end of that time the amount of rust that occurs on the surface of the plate immersed in the water is used as a measure of the effectiveness of the fuel to inhibit rusting in storage vessels.

It is generally preferred that no more than 5 percent of the surface should be rusted.

EXAMPLE 6 AST M Rust Test D-665 I [Inhibitors blended in a fuel oil blend comprising 60% catalytically cracked component and 40% straight run componentapproximately 320-640 F. boiling range] Inhibitor 0011011., Rust Test ppm. Results Blank fuel blend 0 Fail. Blank fuel blend+Ex. 3 5 Pass. Blank fuel blend+Ex. 4-" 5 Pass.

Carburetor Detergency Test The deposit-forming tendencies of a fuel are determined in an 8 hour engine test. This accelerated test, when run on fuels that contain no detergents, produces an amount of deposit equivalent to the amount observed in 4,000 miles of operation in field tests on taxicab fleets. A six-cylinder Chevrolet engine is equipped with notched rings to increase the amount of blowby.' Engine is op erated for 8 hours, using the fuel under test, at alternate idle and running cycles. In the idle cycle, the engine is run at idling speed of 400 r.p.m. with no load, for five minutes. Then, for one minute, the engine is run at a speed of 2500 r.p.m. under a load of 30 B.H.P. and at 9.4 During the running cycle, the blowby and part of the exhaust are released into the carburetor air intake during the idling cycle. After 8 hours operation at alternate run and idle, the carburetor. is examined and rated as to the amount of deposit in the throttle hroat. In the rating scale, a rating of of 0 (zero) indicates a clean carburetor; l=trace deposits; 2=light deposits; 3=medium deposits; and 4=heavy deposits.

EXAMPLE 7 [llllhlbitOlls blenlgel in a fuel toil bileiigqconprisilrig 60% cataytical y crac e componen an a s raig run componentapproxin1ately 320-640" F. boiling range] Inhlbltor 385 3 fiz Inhibitor 00110., lbs./ Screen 4 l 000 bbls. Cloggong Base Fuel 0 0 7 Percent Example4 25' 1.4

Uningibifiegpl lfi gg 8 The ability of the additives, useful for practice of this gfi g tfii g fig gfi ifi 100 22 invention, to inhibit engine stalling was demonstrated Uninhibited 1e 100 '22 by use of the following test and obtainment of the data shown in Example 8.

7 Anti-Stall Test A standard Chevrolet engine, equipped with a Holley single downdraft carburetor, was mounted in a cold room refrigerated to 50 F.

Thermocouple was attached to the throttle plate shaft to record the plate temperature. A /2-inch insulating gasket was placed between the carburetor and manifold to prevent heat conduction. An asbestos sheet covered the entire manifold system to shield the carburetor from convection and radiation. A spray chamber was used to saturate the incoming air with moisture before entering an ice tower which cooled the air to about 35 F.

In conducting a test, the engine was first run for about minutes at 2000 rpm. to bring the engine temperature to equilibrium. The engine was then shut off. When the throttle shaft temperature rose to 40 E, the engine was restarted with the idle speed set at 400 to 500 rpm. so that the base fuel stalled at idle in 10 seconds or less fiter a run-time of 20 to 4-0 seconds. Run-time means the time that the engine was run at 2000 r.p.m. before returning to idle.

All runs were started when the throttle shaft reached 40 F. At the instant of starting, the throttle arm was moved to the 2000 r.p.rn. position and a stop watch started. At the end of the selected run-time, the throttle arm was moved to the idle position. The time required to stall was recorded. Several tests were made at each run-time and averaged.

In evaluating the additive, the base fuel was first tested followed by testing the fuel containing the additive with the system being flushed between tests. Any improvement caused by the additive was reflected in a longer run-time (as compared to the base fuel) to cause stalling in 10 seconds or less when the engine was idled. The more effective the additive, the longer the run time.

EXAMPLE 8 Anti-Stallz'ng Test in Gasoline The demonstrated improvements imparted to petroleum distillates by use of the aforedefined substituted butyric acid derivatives include improvements that are unexpected from such compounds and, especially so, when compared to the performance of similar compounds but which are substituted acetic acid, rather than butyric acid, derivatives. Thus, for example, whereas the butyric acid derivatives embodied for use herein impart a substantial improvement as anti-stall agents in gasolines, the substituted acetic derivative (e.g., nonyl phenoxy acetic acid) has been found to be substantially ineffective for such a purpose.

More specificially, in a gasoline that per se had a stall time of 70 seconds under the conditions of the aforesaid anti-stall test, the presence in such a gasoline of nonyl phenoxy acetic acid at a concentration of 25 lbs.

per thousand barrels of the gasoline resulted in a run time to stall of seconds, i.e.-not a change of practical significance over the run time to stall of the gasoline per se.

Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such variations and modifications are considered to be within the purview and scope of the appended claims.

What is claimed is:

1. As a new liquid composition, a petroleum distillate fraction boiling Within the range of from about 75 F. to about 750 F. containing from about 0.5 to about 200 pounds, per thousand barrels of said fraction, of a substituted butyric acid derivative of the formula in which R is alkyl, x is a whole number of not more than 2 and n is a Whole number of not more than 2.

2. A composition, as defined in claim 1, wherein R is an alltyl group of from about 4 to about 18 carbon atoms.

3. A composition, as defined in claim 1, wherein R is nonyl.

4. A gasoline boiling within the range of from about 75 F. to about 450 F. containing, as an anti-stall agent, from about 0.5 to about 200 pounds, per thousand barrels of said gasoline, of a substituted butyric acid derivative of the formula in which R is alkyl, x is a whole number of not more than 2, and n is a whole number of not more than 2.

5. A petroleum distillate fuel oil boiling within the range of about F. to about 750 F. containing, as an anti-screen clogging agent, from about 0.5 to about 200 pounds per thousand barrels of said fuel oil of a substituted butyric acid derivative of the formula (R): (OCH CHgCH COOH)n in which R is alkyl, x is a whole number of not more than 2, and n is a whole number of not more than 2.

References Cited in the file of this patent UNITED STATES PATENTS 3,012,966 Copes et a1 Dec. 12, 1961 FOREIGN PATENTS 812,938 Great Britain May 6, 1959 815,050 Great Britain June 17, 1959 OTHER REFERENCES Trinidad and Tabago patent, 72/1958, Oct. 9, 1958. 

1. AS A NEW LIQUID COMPOSITION, A PETROLEUM DISTILLATE FRACTION BOILING WITHIN THE RANGE OF FROM ABOUT 75*F. TO ABOUT 750*F. CONTAINING FROM ABOUT 0.5 TO ABOUT 200 POUNDS, PER THOUSAND BARRELS OF SAID FRACTION, OF A SUBSTITUTED BUTYRIC ACID DERIVATIVE OF THE FORMULA 